Android开发获取缓存，删除缓存

news2025/2/13 10:02:25

Android开发获取缓存，删除缓存

app设置中往往有清理缓存的功能。会显示当前缓存时多少，然后可以点击清理缓存

直接上代码：

object CacheHelper {
    /**
     * 获取缓存大小
     * @param context
     * @return
     * @throws Exception
     */

    @JvmStatic
    fun getTotalCacheSize(context: Context): String {
        val cacheSize = getFolderSize(context.cacheDir)
        if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
            // cacheSize += getFolderSize(context.getExternalCacheDir());
        }
        return getFormatSize(cacheSize.toDouble())
    }

    /**
     * 清除缓存
     * @param context
     */
    fun clearAllCache(context: Context) {
        deleteDir(context.cacheDir)
        if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
            deleteDir(context.externalCacheDir)
        }
    }

    private fun deleteDir(dir: File?): Boolean {

        if (dir != null && dir.isDirectory) {
            if (dir.list() == null) {
                return false
            }
            val children = dir.list() ?: return false
            for (i in children.indices) {
                val success = deleteDir(File(dir, children[i]))
                if (!success) {
                    return false
                }
            }
        }
        return dir?.delete() ?: false
    }

    // 获取文件大小
    //Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/ 目录，一般放一些长时间保存的数据
    //Context.getExternalCacheDir() --> SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据
    @Throws(Exception::class)
    fun getFolderSize(file: File): Long {
        var size: Long = 0
        try {
            val fileList = file.listFiles()
            for (i in fileList.indices) {
                // 如果下面还有文件
                size += if (fileList[i].isDirectory) {
                    getFolderSize(fileList[i])
                } else {
                    fileList[i].length()
                }
            }
        } catch (e: Exception) {
            e.printStackTrace()
        }

        return size
    }

    /**
     * 格式化单位
     * @param size
     * @return
     */
    private fun getFormatSize(size: Double): String {
        val kiloByte = size / 1024
        if (kiloByte < 1) {
            // return size + "Byte";
            return "0K"
        }

        val megaByte = kiloByte / 1024
        if (megaByte < 1) {
            val result1 = BigDecimal(java.lang.Double.toString(kiloByte))
            return result1.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "K"
        }

        val gigaByte = megaByte / 1024
        if (gigaByte < 1) {
            val result2 = BigDecimal(java.lang.Double.toString(megaByte))
            return result2.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "M"
        }

        val teraBytes = gigaByte / 1024
        if (teraBytes < 1) {
            val result3 = BigDecimal(java.lang.Double.toString(gigaByte))
            return result3.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "GB"
        }
        val result4 = BigDecimal(teraBytes)
        return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "TB"
    }
}